We want to characterize DD and UD growth cone behavior during embryonic and post embryonic (LI) development of the nematode nervous system. We plan to use multiphoton confocal microscopy and 41) software to observe GFP expressing UD and DD neurons in wild-type and mutant nematodes to better understand the role played by specific molecules in growth cone pathfinding and target recognition. Initial studies will be performed using confocal microscopy. However, it appears likely we will need the multiphoton scope to maintain viability during long term fiequent collection of data sets.